The inventive concept relates to embedded Multimedia Card (eMMC), and more particularly, to eMMC capable of changing clock frequency without performing a clock tuning process. The inventive concept relates to hosts controlling this type of eMMC, as well as methods operating a eMMC systems including this type of eMMC.
The so-called multimedia card (MMC) is a flash memory card standard. The eMMC is an embedded MMC standard defined by the Joint Electron Devices Engineering Council (JEDEC). In general configuration and application eMMCs are designed to be inserted (or “embedded”) in conjunction with a host within mobile communication devices such as smart phones. Conventionally, the eMMC communicates data signals, control signals, commands, clock(s) and/or power signals with the connected host in accordance with a standardize 10-signal bus.
In eMMC systems including a host and eMMC, the host provides the eMMC with a reference (or system) clock signal. In certain embodiments, the clock being provided by the host to the eMMC must be variably defined in its frequency (or clock speed). In order to provide a clock to the eMMC with an appropriate frequency, the host may conventionally perform a specialized procedure referred to as a “tuning process.” The tuning process is used, for example, when increasing the frequency of the clock provided by a host to an eMMC. However, execution of the tuning process increases the eMMC management overhead that must be performed by the host.